In practice, the duration of the standstill phase of a dishwasher machine, that is the time interval between two wash cycles, can be several days. During this standstill phase the dishwasher machine is usually opened and closed again many times to insert dirty items to be washed. Organic constituents on the items to be washed are rapidly decomposed by bacteria as a result of the advantageous conditions prevailing in the interior of a dishwasher machine such as, for example, the temperature, the high humidity, darkness and the enclosed space. This is associated with unpleasant odors which flow towards the user of the dishwasher machine every time the door is opened. The odors are only eliminated by putting the dishwasher machine into operation again.
It would therefore be desirable to provide a dishwasher machine where the user is not exposed to such unpleasant odors even after a fairly long standstill phase.
For sterilising rinsing water, e.g. after a fairly long stoppage time of the dishwasher machine, DE 22 20 189 C2 proposes a dishwasher machine which comprises a UV emitter in the water supply line after the water softener. Similarly, DE 200 14 633 U1 proposes to illuminate the inner area of the dishwasher machine with UV light for the purposes of sterilisation or disinfection. In both cases, however the problem of unpleasant odors during a fairly long standstill phase is not solved with dirty items to be washed stored in the dishwasher machine.
DE 100 36 850 A1 discloses a device and a method for delivering a liquid product with a fragrance-producing or odour-absorbing or antimicrobial-acting active substance in the interior of a dishwasher machine. The device is actuated every time the door of the dishwasher machine is closed. Since the device for delivering the liquid product needs to be exchanged at regular intervals, additional costs are incurred in this case for the user of the dishwasher machine. In addition, it is questionable whether the odour-absorbing substance delivered by the device can still provide its effect to a satisfactory extent after the door has not been actuated for a fairly long time.
For masking odors by incorporating odiferous substances, DE 83 15 008 U1 proposes a disk of plastic material impregnated with an odiferous substance. The device is provided for use in the crockery basket of the dishwasher machine and remains permanently therein. After each crockery wash cycle, the desired improvement in odour occurs as a result of the elevated temperature. No odour improvement can be provided with this arrangement during the standstill phase.
WO 98/12048 discloses the provision of a thin photocatalytic film for use in air flow channels, filter devices and in sections in electrical appliances exposed to a built-in illumination device. This film has an enhanced catalytic effect as a result of various additives. The film can decompose organic substances which are the cause of odors in the air even in weak light. Use within the scope of a wash cycle of a dishwasher machine is described.
EP 0 869 156 B 1 discloses a composite material having a surface which can be made hydrophilic. In this material, one layer contains a photocatalyst consisting of titanium dioxide, photoexcitation being carried out to allow water molecules to adsorb physically onto the surface.
US 2002/0153021 A1 describes an industrial dishwasher machine provided with a conveying device through a washing and a drying zone. The items to be treated by this device are subjected to air drying combined with UV irradiation.
The devices and methods disclosed in the prior art disclose various possibilities for keeping items to be washed in a dishwasher machine as well as the interior of the dishwasher machine sterilised as well as improving odors by means of odiferous substances which are mounted in a storage means and released in a manner coupled to a wash cycle or the actuation of the door. However, the procedures known from the prior art only provide odour improvement to a certain extent since the proposed measures are linked to the execution of a wash cycle or the presence of odiferous substances.